It is known that lapping compounds are used for smoothing or polishing metal surfaces to remove irregularities such as burrs and high spots on these surfaces. For example, it is important for intermeshing gears that the mating surfaces fit together snugly, but without any binding between them. Sometimes the gears will have high spots which due to the close tolerances between the gears, cause them to bind slightly during operation. To eliminate this binding, it is common practice to apply a lapping compound to the high spot. When the gear surface having the high spot meshes with the opposing gear surface, the lapping compound is rubbed across the high spot causing it to be worn down to the level of the remaining portion of the gear surface. When the desired degree of lap is achieved, the lapping compound is then removed.
Another popular use for a lapping compound is the fitting of soft metal bearings and bushings made from such materials as bronze, brass, babbitt and the like. For example, during the fitting of a bronze bushing to a shaft, the lapping compound is applied to the mating surfaces of the bushing and the shaft. As a result, the rotation of the shaft within the bushing causes the lapping compound to act in a sandpaper-like manner to remove any high spots on the mating surfaces and to permit the shaft to rotate easily inside the bushing.
Due to the extremely small tolerances involved when lapping some metal parts, it is highly desirable to control the amount of lapping. Thus the lapping compound should be easily removable from the lapped surface after the desired amount of lap has been achieved.
A number of lapping and abrading compounds have been disclosed. For example, in U.S. Pat. No. 1,381,728 by Menard, a lapping compound is disclosed which includes potassium carbonate or lead sulfate, sodium and an abrasive.
Another lapping composition is discussed by Nelson in U.S. Pat. No. 2,889,215, in which the composition includes a nonviscous mineral oil, a fatty oil, an oil soluble petroleum sulfonate, grease and an abrasive.
Additional lapping compounds include U.S. Pat. No. 1,855,195 by McClaughry which comprises an abrasive, wax, mineral oil, oil soluble sulfonates, as well as soap and water; and Figiel, U.S. Pat. No. 3,663,475, which discusses a compound including diamond powder, alkyl aryl sulfonates and a petroleum based liquid medium.
Also disclosed are various lubricating compositions including U.S. Pat. No. 2,606,872 by Gasser et al in which a composition having an ash forming metallic detergent is added to a lubricating oil to improve the lubricating properties of the oil.
Liehe, in U.S. Pat. No. 2,394,790 discloses a low soap content grease which includes a sulfonic acid soap.
A lubricating grease is disclosed in U.S. Pat. No. Re. 23,082 by Zimmer et al, which includes a mineral lubricating oil and the reaction product of a salt of an oil soluble sulfonic acid and a salt of another acid.
There is also disclosed in U.S. Pat. No. 1,986,243 by Arveson, a polish for automobiles and furniture which comprises a mild abrasive, and a nonvolatile mineral oil.